A calendar event Add-on allows for you to place additional event items for your site users to register/pay for in conjunction with the main event.

For example - if you were having a weekend event with an optional dinner party.  You would list the weekend as an event and then be sure to add the optional dinner as a Add-on to the event. 

This way your users can choose to register for the weekend and simultaneously register for the opt in weekend dinner.  Add-ons also allow for you to charge additional fees for additional aspects of the same event.

*Notes:

1. Calendar event Add-ons are listed as different events in themselves.  They will have their own attendees roster that is separate from the event itself.
2. Calendar event Add-ons are to be actual events in themselves - with a start and end date/time.

This red arrow indicates where the Event Add-on appears on a calendar Event listing:


Click here for more information on Adding calendar event add-ons.